Ms. Valorie: The Part table needs to be manually added to the SSRS Select Query (or added as a Datasaet - not recommended).
Sorry - i wish there was an easy button for this - however, there is not. If you look at the main dataset for the report and go to properties and click on the Fx button for the Querry you will find the report Select Query.
There are a few good videos detailing this process (i would suggest having multiple cups of coffee handy) 
DaveO